Building stops if last material is unaccesible

Summary:
I ordered something to be built as Rayya’s Children (nothing complex, a small regular “square” building) and noticed that after a while my workers have stopped working on it. I double checked if I had clay and I had full stockpiles of it - then I realized that what happened is that the building only required one more “Clay Brick” and it was dropped on top of a wall that later had the scaffolding removed. Dropping materials is not a new “issue” but this time it caused a logic block because it was the last material needed but also unreachable.

Steps to reproduce:
Hard to reproduce being quite the coincidence.
But in theory:

  1. Build clay buildings.
  2. Hope that the last bricks will be dropped on a wall that will have the scaffolding removed

Expected Results:
Building is finished. If materials can’t be reached, crafter should provide more (get a new brick order) OR workers could have the logic of re-building scaffolding during buildings to re-acquire lost/abandoned materials.

Actual Results:
Nothing happens, building is interrupted without giving a proper reason (since I did have the materials, so it doesn’t say I don’t)

Notes:
Builders “dropping” construction materials on top of the building they’re working or simply leaving it on rooftops after it is built is not a new issue - however since that resource is often wood, something they can just grab another down there - it rarely causes a whole construction to stop. In that case, however, being the resource the last bit of Clay Bricks the AI got stuck because they know I have enough but they also couldn’t reach it anymore.

Personally, I’d say that the better approach for this one would be to change the builder’s logic so they don’t just drop materials wherever they are when they stop working but rather try to - if reachable - take materials back to their appropriate stockpiles. This would not only sort out the cosmetic issue of stuff being left on roofs but also prevent situations like this one.

Attachments:

Version Number and Mods in use:
Latest Beta release (r862), DebugTools and one mod that I’m working on but doesn’t touch the building system.